One of my favorite sites is 1000 Awesome Things. I started following it some time into the countdown, so I'm not sure he mentioned this. Regardless, here's my opinion of something truly awesome: The human body!
On Wednesdays I work with a 5th grader and we do science work sometimes so I'm reminded of what I learned years ago. The body has so many parts and systems and yet they all work together!!! Even better, I can tell my body to do something completely crazy - like run 20 miles and it does so! The limiting factors are all in my head. My body can do everything my mind says to.
Then after completely abusing my body through a 20 mile run, it heals itself! That's the most amazing part of all! I didn't do a recovery workout after 20, I didn't get a massage, I just went on with my normal life and my body completely repaired itself in less than 24 hours. How amazing is that?